Roll and Keep Helper

Die roller and probability calculator for role playing games using the roll & keep dice system.

Set a number of 10-sided dice to roll, and a subset of these to be kept. For each roll, the total is compared to a target number.

The Roll and Keep Helper can simulate die rolls and calculate the probability of hitting a target number. It also calculates the probability of successfully calling 1, 2 or 3 raises (hitting increased target numbers).

You can enter the number of dice to roll and keep, the target number, and an optional static bonus using either the + and - keys or you can use a numeric keypad by tapping the number you want to change. Use the tab controls at the bottom to switch between die rolling mode and probability mode. While in die rolling mode, you can shake the phone or press the button to roll the dice.

By default the 10-sided dice will explode on 10s (causing another die to be rolled and added to the total), but the Roll and Keep Helper can be also be set to explode on 9s and 10s, to have no explosions, and/or to reroll 1s once.

No ads or in-game purchases.

Estimating the chance of succeeding on roll & keep die rolls, and how many raises you can safely call, is tricky and I wrote this utility to help. Hope you enjoy it!